74-year-old woman with painless, sudden vision loss in the left eye

The image is consistent with a diagnosis of central retinal artery occlusion (CRAO): 

• Central retinal artery occlusion results from occlusion of the retinal artery, which leads to retinal ischemia and poor vision:
  • Most cases result from embolization of a carotid plaque or cardiogenic thrombus.
  • Less commonly, vasculitides such as giant cell arteritis (GCA) can cause CRAO.
• Most cases present unilaterally with profound vision loss that begins centrally. Sometimes, patients report prior episodes of transient vision loss in the same eye.
• Early intervention and a thorough systemic workup can prevent further ischemic events and sometimes improve vision.

• Call the ophthalmologist emergently!
• Consider performing ocular massage to dislodge the embolus.
• Initiate a systemic workup to identify the occlusion’s etiology:
  • carotid duplex ultrasound to check for carotid atherosclerosis
  • echocardiogram to check for a mural thrombus
  • complete blood count, erythrocyte sedimentation rate, and C-reactive protein to rule out GCA if no embolus is present 
• Initiate an emergent stroke workup: 30% of patients with CRAO will have findings of a stroke on magnetic resonance imaging.

The role of the ophthalmologist includes the following:

• performing the swinging flashlight test to assess for relative afferent pupillary defect
• performing a funduscopic exam with the direct or indirect ophthalmoscope; findings on funduscopic exam include a pale retina, a cherry-red spot in the macula, and narrowed retinal arterioles
• sometimes performing a paracentesis to dislodge the embolus

Although many treatment options exist for acute CRAO, there is no strong evidence for a specific approach.

Prevent life-threatening secondary embolic events such as stroke and heart attack by treating underlying disease found through the systemic workup.

Follow up in 1-4 weeks, as complications such as neovascularization may develop.

Sudden Vision Loss: AAO Interactive Case

Retinal Causes of Vision Loss

Central Causes of Vision Loss

Fundus Diagram: AAO Interactive Figure

Ophthalmology Subspecialties: Medical Retina

Basic Ophthalmology Anki Decks